Sahih Bukhari Volume 005, Book 059, Hadith Number 353.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 59. Military Expeditions Led by the Prophet (PBUH) (Al-Maghaazi)
Narrated By Anas bin Malik: Some men of the Ansar requested Allah's Apostle to allow them to see him, they said, "Allow us to forgive the ransom of our sister's son, 'Abbas." The Prophet said, "By Allah, you will not leave a single Dirham of it!"